FDA to again consider drug aimed at women’s sexual dysfunction

After giving birth to each of her four children and prolonged periods of breast feeding, Amanda Parrish had no desire to have sex with her husband. Her libido died at other times, too, such as when she was in grief after her father’s death, and after her divorce.

But her libido always bounced back. And, in her 40s, when she met Ben Parrish, the man who was to become her second husband, the relationship, she said, was both “emotionally and very sexually charged.” “We had great chemistry,” she said.

Until one day, about three years into their relationship, the desire just stopped. She loved and was still attracted to Ben. She was happy at home and with her work. She wasn’t feeling stressed. She just didn’t have any desire to have sex, with Ben, or anyone. “It was a confusing time,” Ben Parrish said. “I internalized it. I thought I must be doing something wrong.”

Amanda became one of about 11,000 healthy premenopausal women in long-term monogamous relationships diagnosed with Hypoactive Sexual Desire Disorder (HSDD), or low libido, who tried an experimental drug, called flibanserin, one of the very first medications aimed specifically at women’s sexual dysfunction. Parrish said her sex drive returned within two weeks.

But then the Food and Drug Administration rejected flibanserin in 2010 , the clinical trial ended and Parrish had to turn in her unused supply. She said she noticed her desire for sex gradually waning.

A tablet of flibanserin sits on a brochure for Sprout Pharmaceuticals in the company's Raleigh, N.C., headquarters. (Allen Breed/AP)

The Food and Drug Administration said that safety concerns outweighed any benefits, and, in 2013, again rejected the drug for approval.

The manufacturer, Sprout Pharmaceuticals, backed by a host of women’s organizations, resubmitted an application for approval in February with additional safety studies.

And on Thursday, an advisory committee of the FDA will again examine the risks and rewards of the drug. Their vote could influence the final FDA decision, due in August.

At issue is whether the benefits of the drug outweigh side effects like fainting, dizziness, sleepiness and nausea. The committee will also look at flibanserin’s interactions with alcohol and other drugs, particularly birth control pills, which, like flibanserin, are taken on a daily basis.

“The FDA has recognized for a long time that there are women who have reduced sexual desire that causes distress, and who would benefit from safe and effective treatment,” Hylton V. Joffe, director of the FDA’s division of bone, reproductive and urologic products, wrote in a recent memo. “This condition is clearly an area of unmet medical need.”

Medical researchers estimate that about one in every 11 or 12 premenopausal women suffers from low sexual desire that is not related to any other biological, psychological or environmental condition or drug interaction. Antidepressants are known for shutting down desire. Libido can drop temporarily during times of stress. Falling hormone levels after menopause also can depress a woman’s sexual appetite.

“I didn’t understand what was going on,” Amanda Parrish said. “When we had sex, it was more just going through the motions. I couldn’t talk about it. How do you tell the man you love you don’t want to have sex?”

To date, there are no FDA-approved treatments for women with low desire. Viagra, the male sexual function drug that improves blood flow to the genitals, doesn’t treat the problem, which, researchers say, originates in the brain. And the FDA has rejected previous attempts to get testosterone approved for women. That hormone, while it has shown some success in improving desire in women, doesn’t work for everyone, and the side effects can include increased facial hair, more muscle mass and a lower voice.

Although the mechanism isn’t clearly understood flibanserin, works on the serotonin and dopamine receptors in the brain: two key neurotransmitters that work like a seesaw when it comes to sexual desire. The drug was first developed by the pharmaceutical company Boehringer Ingelheim as an antidepressant, until early clinical trials found that, rather than work to relieve depression, it instead boosted the libido of some participants.

When the FDA rejected that company’s initial 2009 application for approval, saying the risks outweighed the benefit, and that the benefit was modest, Sprout Pharmaceuticals took over the drug studies. They resubmitted the application in 2013, arguing that the FDA used an incorrect measure of success — whether the number of sexual episodes or daily desire increased, rather than a longer-term view of increased desire, reduced distress and more satisfying sexual events.

Women, unlike men, proponents of the drug say, can have sex whether they want to or not. So looking for an increase in the number of sexual events may not correlate to a woman’s experience of her own sexual desire.

“Sexual desire can be surrounded by such mythology and folklore. And this has been part of the holdup. Even appreciating what sexual desire is for a woman,” said Cindy Whitehead, CEO of Sprout Pharmaceuticals. “Flibanserin doesn’t create hypersexuality. Women won’t take it and be instantly turned on. That’s not what we’re looking for. We’re looking for a restoration to normal. We feel quite firmly that flibanserin’s modest effect is a meaningful effect.”

The drug has created a political stir. Competing women’s groups have run petition campaigns. On one side, a group led by Even the Score, accuses the FDA of sexism. Viagra was approved in 1998, and other products or medicines for male sexual dysfunction have been approved since then, even though side effects for some of the drugs may damage the heart or result in penile rupture.

“The FDA rejects claims of gender bias,” Joffe of the FDA said in his memo.

On the other side, groups such as the New View Campaign, run by psychologist and sex therapist Leonore Tiefer, argue that pharmaceutical companies are “medicalizing sex” for their own profit. “Sex is complicated,” Tiefer said. “People are greatly benefited by the opportunity to learn about pleasure, emotion, technique. Popping a pill is a shortcut that, like with any shortcut, you end up missing out on everything.”